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(No Model.)

J.A.-BVA.RTS.'

SUSPENSION DEVICE. v No. 365,335. PatentedJune 21, 1887.

N. PETERS. Pmwuum w. Washington, ac.

UNITED STATES] PATENT OFFICE.

- JOHN A. EVART S, OF MERIDEN, CONNECTICUT, ASSIGNOR TO THE BRADLEY & HUBBARD MANUFACTURING COMPANY, OF SAME PLACE.

SUSPENSION DEVICE.

SPECIFICATION forming part of Letters Patent No. 365,335, dated June 21,

Application filed November 4, 1886. Serial No. 217,933. (No model.) I

To aZ? whom, it may concern:

Be it known that I, JOHN A. EVARTS, of Meriden, in the county of New Haven and State of Connecticut, have inventeda new Improvement in Suspension Devices'for Lamps,

8m; and I do hereby declare the following, when taken in connection with accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constltute part of this specification, and represent, 1n-

Figure 1, a side view, part being in section, of the suspension device complete; Fig. 2, a top or plan view of the same; Fig. 3, a modification 1n the application of the constant frictional plate.

This invention relates to an improvementin that class of suspending devices employed for lamps, chandeliers,and like purposes,in which a spr1ng-drum is arranged'to receive thechains by which the lamp is suspended, and so that as the lamp is drawn downward it causes the drum to rotate in one direction to wind the spring, and so that the reaction of the spring may aid in raising the lamp. The same suspending device must be adapted to various weights of lamp or chandelier and to variatlons 1n the weight of the same lamp or chandeller, suchvariation being produced by heavler orlighter shades and founts, or by the variation in the quantityof oil which the fount may contain; hence, if such a'suspending device be adjusted for a certain weight, and so that the spring will counterbalance the weight .of thelamp, any variation of this weight-say by the introduction of a lighter fount or because of less oil, the power of the spring being relieved-will cause the lamp to rise under the reaction of the spring; orif the fount be heavier or the quantity of oil greater, then the spring will not be sufficient to sustain. the lamp, and the lamp will fall accordingly. It is therefore necessary to provide some auxiliary device by 5 which the variations in the weight of the lamp or chandelier nnay be counteracted. This is usually doneby the application of friction. In some cases the friction is constant, so that in drawing down the lamp friction must be over- 50 come, and in raising the lamp the friction must also be overcome; but in thus raising the lamp the power of the spring is diminished by so much as the friction applied. In other cases the friction has been applied as the lamp is drawn downward, so as to increase the resistance to drawing down, yet be automatically relieved as the lamp is raised, so as to leave the spring entirely free to lift; but if the friction be entirely removed in the ascent, then wheneverthe power of the spring overbalances the weight of the lamp the spring is free, and the result is that the lamp will be raised, or continue its rise when once started.

The object of my invention is to apply a certain amount of constant friction, together with a relieved friction-that is, a friction which will be applied as the lamp is drawn downward, but relieved as the lamp is raisedso that in drawing down the lamp the com bined friction will be applied, but as thelamp 7c is raised one friction will be relieved, the other remaining constant.

In illustrating the invention Ishow it as ap plied to a suspension device in which the spring-drum is arranged upon a vertical axis, and so as to revolve in a horizontal plane.

A represents the frame; B, the spring-drum, aroundwhich thech'ainsarewound,onechain,a, passing overaguidepulley, C, at one side of the frame, and the other chain, 1), over a like guideso pulley, D, at the opposite side of the frame, the frame being provided with a loop, E, or other device by which it may be suspended.- The springdrum contains the usual coiled spring, one end of which is secured to a fixed 8 5 axis, and the other end of the spring fixed to the drum, so that as the chains are drawn downward and revolve the drum in one direction it will cause the spring to be wound; but as thechains and spring are left free the reaction of the spring will cause the drum to revolve in the oppositedirection andwind the chains thereon. This is a common and wellknown construction, and. does not require detailed description. Upon one end of the drum '95 a plate, F, is arranged independent of 'the drum, but so as to stand in frictional contact therewith. The adjacent surfaces of the drum and plate may come in actual metal contact, or a flexible material like leather or india- I00 rubber may be introduced between to increase the friction. The drum works in rubbing contact with the plate or intermediate material. The plate is supported upon an axis concentric with the drum, in the usual manner of supporting friction plates upon the drum. This plate is held so as to prevent its revolving when the drum revolves in the direction of winding the spring-that is, drawing down the chains-but when the drum turns in the opposite direction the plate is free to revolve with the drum. This holding and releasing of the plate may be performed by any of the wcllknown devices for so doing; but I prefer to construct the plate with a concentric flange, G, upon its upper or outer surface, and ppon the frame I hang a dog, H, which stands in substantially a radial position to the plate. The dog extends over the flange, and is constructed with a notch, I, so as to embrace the flange. (See Fig. 1.) The dog is free for a certain amount of play in a plane parallel with the plane of the plate F, as indicated in broken lines, Fig. 2. The direction of revolution of the drum in winding the spring or drawing down the chains is indicated by the arrow in Fig. 2, and the dog H is upon that side of the frame from which the drum rev'olves in winding the spring, as seen in Fig. 2. As the drum revolves in drawing down the chains it causes the plate F to re volve with it, because of the frictional contact between the two. The frictional contact be tween the flange G of the plate F and the free end of the dog H causes the dog to turn upon its pivot d and its free end to follow with the flange in its revolution until it arrives at a point, say as seen in broken lines, Fig. 2, where the notch I cramps upon the flange; then the plate F will be held fast, and the furtherrcvolution ofthe drum will be independent of the plate, and its revolution will be resisted by the friction between the plate F and the drum; but when the reaction of the spring is permitted the drum revolves in the opposite direction, taking with it the plate F, and the free end of the dog is returned against the frame or other suitable stop, as seen in Fig. 2, and into a position in which the flange will run free through the'notch in the dog; hence the plate F will continue to revolve with the drum so long as the drum revolves in this lifting direction. The frictional action of the plate F is therefore applied when the chains are drawn from the drum; but its frictional action is entirely removed when the drum revolves in the opposite direction. As a constant friction, I arrange between the plate F and the frame upon that side a fixed springplate, J, the plate J resting upon the plate F, and its two ends preferably turned upward to take an elastic bearing inside that side of the frame, as seen in Fig. 1, and so as to prevent the revolution of the plate J in either direction; hence the spring-plate J is held in frietional contact with the plate F in either direction in which the plate F may revolve, and

consequently producesa constant friction upon the drum; but the friction between the plate J and the plateF must be less than the friction between the plate F and the drum, in order that the plate F may revolve with the drum when free from the dog H.

Instead of making the plate J an elastic plate, the spring or elasticity may be imparted by an independent spring, as seen in Flg. 3, the spring adapted to bear upon the plate and hold it in frictional contact with the plate F,

The constant-friction plate J may be omitted and the friction-plate F, with the cramping dog H, employed, so as to produce only the relieved friction; or the auxiliary frlctlonplate may be employed with any known rellef friction-plate.

From the foregoing it will be understood that I am aware of suspension devices for lamps, &c., consisting of a springdrum, the

spring of which is adapted to wind the chain or cord upon the drum, combined with a concentric plate arranged to bear against one head of the drum, with a spring adapted to bear upon said plate and force it against the drum, and a dog to hold such plate stationary while the drum revolves in one direction, yet leave the plate free to revolve with the'drum in the opposite direction, and whereby the friction of the plate is applied to the drum when the plate is so held, and the drum is relieved from the friction when the plate revolves with it; and I therefore do not claim, broadly, such a device, the essential feature of this part of my invention being the peculiar construction of the plate and the dog, whereby, instead of a pawl-and-ratehet connection to hold the plate in one direction and permit it to revolve in the opposite direction, I employ a concentric flange on the plate and a dog hung in the frame and so as to swing in a plane parallel with the plate, the dog extending over the concentric flange on the plate, and the said dog constructed with a notch of greater width than the thickness of the flange, whereby as the plate revolves in one direction the flange will work freely through the notch in the dog, but when turning in the opposite direction the notch in the dog will cramp upon the flange, so as to hold the plate stationary while the drum revolves.

I claim- 1. In a suspension device, the combination of a frame, a spring-drum arranged upon an axis in said franie,and a chain or chains wound upon said drum under the reaction of the spring of the drum, a frictional plate adapted to bear upon one end of the drum, the said plate constructed with a concentric flange, G, upon its outer surface, a dog, H, hung to the frame so as to swing in a plane parallel with the plane of the plate and extending over the flange, said dog constructed with a notch, I, of greater width than the thickness of the said flange and adapted to embrace said flange, substantially as described, and whereby as the drum revolves in one direction the friction- IIO platewill be held by the cramping action of the said dog, and revolving in the opposite direction will be free therefrom.

2. In a suspension device, the combination of a frame, a spring-drum arranged upon an axis within said frame,a chain or chains wound upon the said drum under the reaction of the drum-spring',a frictional plate adapted to bear upon one end of said drum, and a dog arranged to hold said frictional plate and prevent its revolution with the drum in one direction, but'leave it free to revolve with the drum in the opposite direction, with an auxiliary spring friction-plate adapted to produce a constant friction upon said drum, and in addition to the friction between the said plate F and the drum, substantially as described.

JOHN A. EVARTS. Witnesses:

FRANCIS B. FAIRBANKS, HORACE S. SAVAGE. 

